An Investigation into Transport Protocols and Data Transport ...

9.3. Internet Transfers 232
1000
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Goodput (mbit/sec)
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0
Standard TCP HSTCP ScalableTCP HTCP FAST BicTCP
New−TCP
Figure 9.27: Goodput from CERN to Stanford.
that results could be gathered. This was achieved by setting the initial value
of ssthresh upon a TCP connection to 2 segments rather than max(INT). The
effect of disabling slow-start would be similar to the effects of large bursts of
transient cross traffic which would similarly cause slow-start to exit early.
9.3.2 Results: CERN to Stanford
Goodput
Figure 9.27 shows the goodput performance distributions of the various New-
TCP algorithms from CERN to Stanford, California, U.S.. It clearly shows
the consistent inability of Standard TCP to achieve reasonable goodput over
such long distance paths.
For the other New-TCP algorithms, the results show a large range of
measured goodput performances with symmetric distribution of goodputs.
Most notably all algorithms have a minimum which is near zero, suggesting
that that the network load can be high, thus preventing high performance
network transfers.
Whilst it is clear that FAST is able to achieve the highest median goodput
performance, it also has the widest distribution. The high maximum also